Project Summary/Abstract Minnesota HealthSolutions (MHS) proposes to develop an advanced harness system for motor vehicle child safety seats. Motor vehicle crashes are the leading cause of death for American children. A total of 2,590 children aged 12 years or younger died as a result of unintentional motor vehicle traffic crashes from 2010-13 and hundreds of thousands more were injured. When used properly, child safety seats are the most effective way to protect young children involved in motor vehicle crashes from serious injury or death. A child safety seat harness, typically a 5-point seat belt webbing system, restrains the child in the seat. The tightness of the harness on the child's torso at the onset of the crash is directly related to the amount of head excursion experienced by the child and any slack in the harness at the time the child is buckled into the seat results in increased head excursion. Head excursion is closely linked with head injuries in children during crashes. Despite the importance of correctly tensioning the harness, it is often under-tensioned. A common reason that harnesses are so often under- tensioned is the fact that harness tensioning is physically difficult, particularly in the rear-facing position, in smaller vehicles, for physically weak or disabled persons, for persons who are unable to fit inside the rear of a vehicle with a child safety seat, etc. Improvements are needed in child safety seat design to decrease the prevalence of improper harness tensioning. A novel new child safety seat is proposed to address this need and reduce head injuries in children during crashes.